Ultrathin optical panel and a method of making an ultrathin optical panel

ABSTRACT

An ultrathin optical panel, and a method of producing an ultrathin optical panel, are disclosed, including stacking a plurality of glass sheets, which sheets may be coated with a transparent cladding substance or may be uncoated, fastening together the plurality of stacked coated glass sheets using an epoxy or ultraviolet adhesive, applying uniform pressure to the stack, curing the stack, sawing the stack to form an inlet face on a side of the stack and an outlet face on an opposed side of the stack, bonding a coupler to the inlet face of the stack, and fastening the stack, having the coupler bonded thereto, within a rectangular housing having an open front which is aligned with the outlet face, the rectangular housing having therein a light generator which is optically aligned with the coupler. The light generator is preferably placed parallel to and proximate with the inlet face, thereby allowing for a reduction in the depth of the housing.

CROSS REFERENCE TO RELATED APPLICATIONS

[0001] This application is a continuation-in-part of U.S. patentapplication Ser. No. 09/145,411, filed Aug. 31, 1998, and entitled“ULTRATHIN DISPLAY PANEL”.

STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT

[0002] This invention was made with federal government support undercontract number DE-AC02-98CH10886, awarded by the U.S. Department ofEnergy. The government has certain rights in the invention.

BACKGROUND OF THE INVENTION

[0003] 1. Field of the Invention

[0004] The present invention relates to planar optical displays, and,more particularly, to an ultrathin display panel and a method of makingan ultrathin display panel.

[0005] 2. Description of the Background

[0006] Optical screens typically use cathode ray tubes (CRTs) forprojecting images onto the screen. The standard screen has a width toheight ratio of 4:3 with 525 vertical lines of resolution. An electronbeam is scanned both horizontally and vertically-across the screen toform a number of pixels which collectively form the image.

[0007] Conventional cathode ray tubes have a practical limit in size,and are relatively deep to accommodate the required electron gun. Largerscreens are available which typically include various forms of imageprojection. However, such screens have various viewing shortcomingsincluding limited viewing angle, resolution, brightness, and contrast,and such screens are typically relatively cumbersome in weight andshape. Furthermore, it is desirable for screens of any size to appearblack in order to improve viewing contrast. However, it is impossiblefor direct view CRTs to actually be black because they utilize phosphorsto form images, and those phosphors are non-black.

[0008] Optical panels may be made by stacking waveguides defining awedge and having a narrow inlet face along the bottom of the wedge and avertical outlet screen disposed obliquely to the inlet face. Such apanel may be thin in its depth compared to its height and width, and thecladding of the waveguides may be made black to increase the blacksurface area, but such a panel may require expensive and cumbersomeprojection equipment to distribute the image light across the narrowinlet face, which equipment thereby increases the total size of thepanel.

[0009] Therefore, the need exists for an optical panel which possessesthe advantages corresponding to a stacked waveguide panel, but whichdoes not require the use of expensive and cumbersome projectionequipment, nor suffer from the increase in size necessitated by suchequipment.

SUMMARY OF THE INVENTION

[0010] The present invention is directed to an ultrathin optical panel.The panel includes a plurality of stacked optical waveguides, whereinthe plurality forms an outlet face and an inlet face, and at least onecoupler connected to the inlet face which redirects light along anon-perpendicular axis to the inlet face to a perpendicular axis to theinlet face. The coupler allows the panel to be created using simplelight generating equipment, and allows that equipment to be mounted inclose proximity with the inlet face.

[0011] The present invention is also directed to a method of producingan ultrathin optical panel. The method includes vertically stacking aplurality of glass sheets, which sheets may be coated with a transparentcladding substance or may be uncoated, fastening together the pluralityof stacked coated glass sheets using an epoxy or ultraviolet adhesive,applying uniform pressure to the stack, curing the stack, sawing thestack to form an inlet face on a side of the stack and an outlet face onan opposed side of the stack, bonding a coupler to the inlet face of thestack, and fastening the stack, having the coupler bonded thereto,within a rectangular housing having an open front which is aligned withthe outlet face, the rectangular housing having therein a lightgenerator which is optically aligned with the coupler.

[0012] The present invention solves problems experienced in the priorart, such as the required use of expensive and cumbersome projectionequipment, by providing a light inlet which, though smaller in surfacearea than the outlet face, is large enough and symmetrical enough to notnecessitate the use of expensive projection equipment. The presentinvention also retains the advantages which correspond to a stackedwaveguide panel, such as improved contrast and minimized depth.

[0013] Those and other advantages and benefits of the present inventionwill become apparent from the detailed description of the inventionhereinbelow.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

[0014] For the present invention to be clearly understood and-readilypracticed, the present invention will be described in conjunction withthe following figures, wherein:

[0015]FIG. 1 is an isometric view schematic illustrating an opticalpanel;

[0016]FIG. 2 is a side view cross sectional schematic of an ultrathinoptical panel; and

[0017]FIG. 3 is a schematic illustrating a horizontal and vertical crosssection of an ultrathin display panel using a prismatic coupler.

DETAILED DESCRIPTION OF THE INVENTION

[0018] It is to be understood that the figures and descriptions of thepresent invention have been simplified to illustrate elements that arerelevant for a clear understanding of the present invention, whileeliminating, for purposes of clarity, many other elements found in atypical optical display panel. Those of ordinary skill in the art willrecognize that other elements are desirable and/or required in order toimplement the present invention. However, because such elements are wellknown in the art, and because they do not facilitate a betterunderstanding of the present invention, a discussion of such elements isnot provided herein.

[0019]FIG. 1 is an isometric view schematic illustrating an opticalpanel 10. The optical panel 10 includes a plurality of waveguides 10 a,wherein one end of each waveguide 10 a forms an inlet for thatwaveguide, and wherein the opposite end of each waveguide 10 a forms anoutlet for that waveguide 10 a, a light generation system 12, a housing14 in which the light generation system 12 and the plurality ofwaveguides 10 a are mounted, and a coupler 16.

[0020] Each waveguide 10 a extends horizontally, and the plurality ofstacked waveguides 10 a extends vertically. The plurality of inlet endsdefine an inlet face 20 for receiving image light 22. The plurality ofoutlet ends define an outlet face 24 disposed substantially parallelwith the inlet face 20 for displaying light 22. The light 22 may bedisplayed in a form such as, but not limited to, a video image 22 a.

[0021] The housing 14 is sized larger in height and width than thecombination of the light generation system 12 and the plurality ofwaveguides 10 a, to allow the placement of the plurality 10 a and lightgeneration system 12 therein. The housing 14 has an open front to allowfor viewing of the outlet face 24, and has a closed depth D looking fromthe open front to the back of the housing 14.

[0022] The light generation system 12 provides the light viewed throughthe waveguides 10 a. The light generation system 12 includes a lightsource 30, and a light redirection element 32 that redirects incidentlight 22 from the light source 30 into the coupler 16, which lightredirection element 32, in combination with the coupler 16, allows for areduction in the depth D of the housing 14. This reduction allowanceoccurs where the light redirection element 32 is configured for turningthe light 22 from a source 30, which source 30 is placed within thehousing 14 proximate to and parallel with the vertical stack of theplurality of waveguides 10 a, into the coupler 16, which then acutelyturns the light 22 into the waveguides 10 a. The coupler 16 ispreferably effective for turning the image light in an exemplary rangeof about 45° up to about 90°, in order to generate approximatelyhorizontal transmission through the plurality of waveguides 10 a. Thelight generation system 12 may also include a modulator and furtherimaging optics. The light generation system 12 is discussed with moreparticularity with respect to FIG. 2.

[0023] The parallel surfaces of the inlet face 20 and the outlet face 24allow the panel 10 and enclosing housing 14 to be made ultrathin indepth. The panel 10 has a nominal thickness T which is the depth of thewaveguides 10 a between the inlet face 20 and the outlet face 24, andthickness T is substantially less than the height H and width W of theoutlet face 24. The panel 10 may be configured in typical televisionwidth to height ratios of 4:3 or 16:9, for example. For a height H ofabout 100 cm and a width W of about 133 cm, the panel thickness T of thepresent invention may be about 1 cm. The depth D may vary accordinglywith the thickness T, but, in the embodiment described hereinabove, thedepth D of the housing 14 is preferably no greater than about 12 cm.

[0024]FIG. 2 is a side view cross sectional schematic of an ultrathinoptical panel 10. The panel 10 includes a plurality of stackedwaveguides 10 a, a light generation system 12, a coupler 16, and ahousing 14.

[0025] The light generation system 12, in one embodiment of the presentinvention, includes a projector 60 which is optically aligned with alight redirection element 32. An image is projected onto the lightredirection element 32, and is then redirected to the coupler 16 fortransmission through the waveguides 10 a for display on the outlet face24. In a preferred embodiment, the projector 60 is disposed adjacent tothe top of the inlet face 20 for projecting the image light 22 generallyparallel thereto, and is spaced therefrom a distance sufficient to allowfor a turning of the image light 22 from the light redirection element32 into the coupler 16 for transmission through the waveguides 10 a.

[0026] The projector 60 may include a suitable light source 30 forproducing the light 22 The light source 30 may be a light bulb, slideprojector, video projector, or laser, for example. The projector 60 mayalso include a modulator 62 for modulating the light 22 to form an image22 a. The-modulator 62 may be, for example, a conventional LiquidCrystal Display (LCD), a Digital Micromirror Device (DMD), a GLV, alaser raster scanner, a PDLC, an LCOS, a MEMS, or a CRT. The projector60 may also include suitable image optics 64 for distributing orbroadcasting the image light 22 horizontally and vertically across thelight redirection element 32 for properly focused transmission to thecoupler 16. The image optics 64 may include focusing and expandinglenses and mirrors. One or more light generation systems 12, such asbetween 2 and 4 such systems, may be used to provide light to one ormore portions of the coupler 16. Expansion lenses may be used for boththe imaging optics 64 and the light redirection element 32 to expand theimage light 22 both vertically and horizontally over the coupler 16.Alternatively, suitable rastering systems may be used as the lightgeneration system 12 to form the image by rastering the image light 22both horizontally and vertically across the coupler 16.

[0027] In the illustrated embodiment, the light 22 is initiallyprojected from the projector 60 vertically downward inside the housing14 to the bottom thereof where the light redirection elements 32 aremounted, and the light redirection elements 32 then redirect the imagelight 22 vertically upwardly at a small acute angle for broadcast overthe entire exposed surface of the coupler 16. In an alternativeembodiment, the projector 60 could be placed beneath the inlet face 20rather than behind the inlet face 20.

[0028] The allowable incidence angle of the image light 22 on thecoupler 16 is determined by the capability of the coupler 16 to turn thelight 22 into the inlet face 20 of the panel 10. The greater the turningcapability of the coupler 16, the closer the projector 60 may be mountedto the coupler 60 for reducing the required depth D of the housing 14.

[0029]FIG. 3 is a schematic illustrating a horizontal and vertical crosssection of an ultrathin optical panel 10. The panel 10 includes aplurality of vertically stacked optical waveguides 10 a, a lightgeneration system 12 (see FIG. 2), a coupler 16, and a housing 14. Eachwaveguide 10 a of the plurality of waveguides 10 a includes a centraltransparent core 80 having a first index of refraction. The core 80 maybe formed of any material known in the art to be suitable for passingelectromagnetic waves therethrough, such as, but not limited toplexiglass or polymers. The central core 80 may be formed of an opticalplastic, such as Lexan®, commercially available from the GeneralElectric Company®, or glass, such as type BK7. The preferred embodimentof the present invention is implemented using individual glass sheets,which are typically in the range between 2 and 40 microns thick, andwhich may be of a manageable length and width. The central core 80 islaminated between at least two cladding layers 82. The cladding layers82 immediately in contact with the glass have a second index ofrefraction lower than that of the cores 80, thus allowing forsubstantially total internal reflection of the light 22 as it istransmitted through the cores 80. The cladding 82 may be a suitableplastic, glass, plastic, polyurethane, low refractive index polymer, orepoxy, for example, and is preferably black in color. Where multiplecladding layers 82 are used, it is preferable that a clear claddinglayer contact the glass, and a black cladding layer be disposed betweenadjacent clear cladding layers, thus improving both viewing contrast ofthe outlet face 24 and internal reflection of the light 22 through thecore 80. The use of at least one black cladding layer 82 providesimproved contrast by providing additional blackness at the outlet face24. Further, the exposed edges of the black cladding 82 at the outletface 24 are directly viewable to the observer. Additionally, ambientlight which enters the waveguides off-axis through the outlet face 24will be absorbed-internally by the black cladding 82. The black cladding82 may be formed in any suitable manner such as with black spray paint,or carbon particles within an epoxy adhesive joining together theadjacent cores 80 in one or more black cladding layers 82. The manner offorming the cladding layers 82 and cores 80 is discussed with morespecificity hereinbelow.

[0030] The waveguides 10 a of the preferred embodiment are in the formof flat ribbons extending continuously in the horizontal direction alongthe width of the outlet face 24. The ribbon waveguides 10 a arepreferably stacked vertically along the height of the outlet face 24.The vertical resolution of the panel 10 is thus dependent on the numberof waveguides 10 a stacked along the height of the outlet face 24. Forexample, a stacking of 525 waveguides would provide 525 vertical linesof resolution.

[0031] The plurality of stacked waveguides 10 a may be formed by firstlaying a first glass sheet in a trough sized slightly larger than thefirst glass sheet. The trough may then be filled with a thermally curingepoxy. The epoxy is preferably black, in order to form a black layerbetween waveguides, thereby providing improved viewing contrast.Furthermore, the epoxy should possess the properties of a suitablecladding layer 82, such as having a lower index of refraction than theglass sheets to allow substantially total internal reflection of thelight 22 within the glass sheet. After filling of the trough, glasssheets 80 are repeatedly stacked, and a layer of epoxy forms betweeneach glass sheet 80. The stacking is preferably repeated until betweenapproximately 500 and 800 sheets have been stacked. Uniform pressure maythen be applied to the stack, thereby causing the epoxy to flow to agenerally uniform level between glass sheets 80. In a preferredembodiment of the present invention, the uniform level obtained isapproximately 0.0002″ between glass sheets 80. The stack may then bebaked to cure at 80 degrees Celsius for such time as is necessary tocure the epoxy, and the stack is then allowed to cool slowly in order toprevent cracking of the glass. After curing, the stack may be placedagainst a saw, such as, but not limited to, a diamond saw, and cut to adesired size. The cut portions of the panel 10 may then be polished witha diamond polisher to remove any saw marks.

[0032] In an alternative embodiment of the present invention, aplurality of glass sheets 80 are individually coated with, or dippedwithin, a substance having an index of refraction lower than that of theglass, and the plurality of coated sheets are fastened together usingglue or thermally curing epoxy, which is preferably black in color. Afirst coated glass sheet 10 a is placed in a trough sized slightlylarger than the first coated glass sheet 10 a, the trough is filled witha thermally curing black epoxy, and the coated glass sheets 10 a arerepeatedly stacked, forming a layer of epoxy between each coated glasssheet 10 a. The stacking is preferably repeated until betweenapproximately 500 and 800 sheets have been stacked. Uniform pressure maythen be applied to the stack, followed by a cure of the epoxy, and asawing of the stack into a desired size. The stack may be sawed curvedor flat, and may be frosted or polished after sawing.

[0033] In another alternative embodiment of the present invention, theglass sheets 80 preferably have a width in the range between 0.5″ and1.0″, and are of a manageable length, such as between 12″ and 36″. Thesheets 80 are stacked, with a layer of black ultraviolet adhesive beingplaced between each sheet 80. Ultraviolet radiation is then used to cureeach adhesive layer, and the stack may then be cut and/or polished.

[0034] After sawing and/or polishing the stack, each of the aboveembodiments of the method also includes bonding a coupler 16 to theinlet face 20 of the stack, and fastening the stack, having the coupler16 bonded thereto, within the rectangular housing 14. The stack isfastened such that the open front of the housing 14 is aligned with theoutlet face 24, and the light generator 12 within the housing 14 isoptically aligned with the coupler 16.

[0035] The light generation system 12 provides light 22 which isincident on the coupler 16, and is substantially as discussed withrespect to FIG. 2. The source 30 of the light generation system 12 maybe mounted within the housing 14 in a suitable location to minimize thevolume and depth of the housing 14. The source 30 is preferably mountedwithin the housing 14 directly behind the inlet face 20 at the topthereof to initially project light 22 vertically downwardly, which lightis 22 then turned by elements 32 of the light generation system 12vertically upwardly to optically engage the coupler 16. In the preferredembodiment of the present invention, the individual waveguides 10 aextend horizontally without inclination, thus allowing the image to betransmitted directly horizontally through the waveguides 10 a for directviewing by an observer, thereby allowing the viewer to receive fullintensity of the light 22 for maximum brightness. Thus, for maximumbrightness, the light 22 incident from the light generation system 12must be turned substantially horizontally. A prismatic coupler 16 may beused to turn the light at an angle up to 90 degrees for entry into theinlet face 20. In one embodiment of the present invention, a TRAF turnsthe light at an angle of 81 degrees.

[0036] The light coupler 16 adjoins the entire inlet face 20 and may besuitably bonded thereto for coupling or redirecting the light 22incident from the light generation system 12 into the inlet face 20 fortransmission through the waveguides 10 a. The waveguides 10 a of thepresent invention may have a limited acceptance angle for receivingincident light 22, and the coupler 16 is aligned to ensure that theimage light 22 is suitably turned to enter the waveguide cores 80 withinthe allowable acceptance angle.

[0037] In a preferred embodiment of the present invention discussedhereinabove, the coupler 16 includes fresnel prismatic grooves 16 a thatare straight along the width of the inlet face 20 and are spacedvertically apart along the height of the inlet face 20, which prismaticcoupler 16 is capable of turning light up to an angle of 90 degrees. Ina preferred embodiment of the present invention, the prismatic coupler16 is a Transmissive Right Angle Film (TRAF) commercially available fromthe 3M Company® of St. Paul, Minneapolis, under the tradename TRAF II®.An optional reflector may be disposed closely adjacent to the prismaticcoupler 16 for reflecting back into the waveguides 10 a any stray light22 at the grooves 16 a.

[0038] The coupler 16 may also take the form of a diffractive element16. The diffractive coupler 16 includes a diffractive grating having alarge number of small grooves extending horizontally and parallel withthe individual waveguides 10 a, which grooves are closely spacedtogether in the vertical direction over the height of the inlet face 20.The coupler 16 may take other forms as well, including, but not limitedto, holographic elements.

[0039] The housing 14 supports the waveguide stack 10 a and the lightgeneration system 12 in a substantially closed enclosure. The outletface 24 faces outwardly and is exposed to the viewer and ambient light,and the inlet face 20 and adjoining coupler 16 face inwardly toward thepreferably black surfaces within the housing 14, thereby providingadditional black for contrast at the outlet face 24. This additionalblack is provided at the outlet face 24 due to the passive nature of thewaveguides 10 a and the coupler 16. When these passive devices areenclosed in a black area, the outlet face 24 will appear black when notilluminated by image light 22 incident on the inlet face 20.

[0040] Those of ordinary skill in the art will recognize that manymodifications and variations of the present invention may be implementedThe foregoing description and the following claims are intended to coverall such modifications and variations.

What is claimed is:
 1. An optical panel, comprising: a plurality ofstacked optical waveguides, each having a first end and a second end,wherein an outlet face is defined by the plurality of first ends, andwherein an inlet face is defined by the plurality of second ends, theinlet face being substantially parallel to the outlet face; and at leastone coupler connected to the inlet face which redirects light along anon-perpendicular axis to the inlet face to a perpendicular axis to theinlet face.
 2. The optical panel of claim 1, further comprising at leastone light generation system.
 3. The optical panel of claim 2, whereinsaid light generation system includes: a light source; and at least onelight redirection element that redirects incident light from the lightsource into said coupler.
 4. The optical panel of claim 3, wherein thelight source is adjacent to and parallel with the inlet face, andwherein the light source emits light parallel to the inlet face from atop to a bottom of the inlet face.
 5. The optical panel of claim 3,wherein the light source is selected from the group consisting of alight bulb, a slide projector, a video projector, and a laser.
 6. Theoptical panel of claim 3, wherein said coupler turns the light into theinlet face at an angle in the range of about 45° to about 90°.
 7. Theoptical panel of claim 3, wherein said light generation system furtherincludes a modulator and imaging optics.
 8. The optical panel of claim2, wherein said light generation system includes: a light redirectionelement; and a projector which is optically aligned with the lightredirection element.
 9. The optical panel of claim 8, wherein theprojector projects light onto the light redirection element, which lightis redirected by the light redirection element to said coupler.
 10. Theoptical panel of claim 9, wherein the projector is disposed beneath theinlet face.
 11. The optical panel of claim 9, wherein the projector isdisposed adjacent to the top of the inlet face for projecting the lightgenerally parallel to the inlet face, and is spaced from the inlet faceto allow turning of the light from the light redirection element intosaid coupler.
 12. The optical panel of claim 9, wherein the projectorincludes a light source for producing the light, and a modulator formodulating the light to form an image.
 13. The optical panel of claim12, wherein the modulator is selected from the group consisting of aLiquid Crystal Display, a Digital Micromirror Device, a GLV, a laserraster scanner, a PDLC, an LCOS, a MEMS, and a CRT.
 14. The opticalpanel of claim 12, wherein the projector includes image optics fordistributing the light horizontally and vertically across the lightredirection element.
 15. The optical panel of claim 14, wherein theimage optics include focusing lenses and mirrors.
 16. The optical panelof claim 15, wherein the image optics and the light redirection elementcomprise expansion lenses.
 17. The optical panel of claim 2, whereinbetween 2 and 4 light generation systems provide light to said coupler.18. The optical panel of claim 2, wherein said light generation systemcomprises a rastering system which rasters light horizontally andvertically across said coupler.
 19. The optical panel of claim 2,further comprising a housing having a front, a back, two sides, a top,and a bottom.
 20. The optical panel of claim 19, wherein said housingencloses said light generation system and said plurality of waveguidestherein.
 21. The optical panel of claim 19, wherein the front of saidhousing is open, and wherein said housing has a closed depth lookingfrom the open front to the back of the housing.
 22. The optical panel ofclaim 21, wherein the closed depth is about 12 cm.
 23. The optical panelof claim 21, wherein the top, the bottom, the two sides, and the backeach have an interior adjacent to the inlet face, and an exterior, andwherein the interior of the top, the bottom, the back, and the two sidesare black in color.
 24. The optical panel of claim 1, wherein eachwaveguide extends horizontally, and the plurality of stacked waveguidesextends vertically along the outlet face.
 25. The optical panel of claim1, wherein light is displayed on the outlet face as a video image. 26.The optical panel of claim 1, wherein the plurality of waveguides has athickness along a perpendicular axis from the inlet face to the outletface, which thickness is less than a height and a width of the outletface.
 27. The optical panel of claim 26, wherein the width and theheight have a ratio of 4:3.
 28. The optical panel of claim 27, whereinthe height of the outlet face is about 100 cm, the width of the outletface is about 133 cm, and wherein the thickness is about 1 cm.
 29. Theoptical panel of claim 1, wherein each waveguide of said plurality ofwaveguides includes a central transparent core having a first index ofrefraction, which central core is disposed between at least two claddinglayers.
 30. The optical panel of claim 29, wherein the central core isformed of a material selected from the group consisting of a polymer, aplastic laminate, and glass.
 31. The optical panel of claim 30, whereinthe glass is of type BK7.
 32. The optical panel of claim 30, wherein theglass is formed into sheets having a thickness in the range betweenabout 2 and 40 microns.
 33. The optical panel of claim 30, wherein thecentral core is laminated between the at least two cladding layers. 34.The optical panel of claim 30, wherein the cladding layers immediatelyin contact with the central core have a second index of refraction lowerthan the first index of refraction.
 35. The optical panel of claim 30,wherein the cladding is selected from the group consisting ofplexiglass, glass, plastic, polyurethane, a low refractive indexpolymer, and epoxy.
 36. The optical panel of claim 30, wherein onecladding layer is disposed between adjacent central cores, and is blackin color.
 37. The optical panel of claim 30, wherein at least twocladding layers are disposed between adjacent central cores, and whereinone of the cladding layers is black in color.
 38. The optical panel ofclaim 37, wherein a clear cladding layer contacts the central core, anda black cladding layer is disposed between adjacent clear claddinglayers.
 39. The optical panel of claim 36 or claim 37 or claim 38,wherein the black cladding layer is formed of a material selected fromthe group consisting of black spray paint and carbon particles within anepoxy adhesive joining together adjacent central cores.
 40. The opticalpanel of claim 1, wherein each of said plurality of waveguides areformed as flat ribbons extending continuously in a horizontal directionalong the outlet face.
 41. The optical panel of claim 1, wherein saidplurality of stacked waveguides comprises a stack of between about 500and about 800 waveguides.
 42. The optical panel of claim 1, wherein eachof said plurality of stacked waveguides is stacked without inclination.43. The optical panel of claim 1, wherein said coupler is a prismaticcoupler.
 44. The optical panel of claim 43, wherein said prismaticcoupler includes fresnel prismatic grooves that are straight along ahorizontal of the inlet face and are spaced apart along a vertical ofthe inlet face.
 45. The optical panel of claim 44, wherein saidprismatic coupler turns light at an angle up to about 90 degrees. 46.The optical panel of claim 45, wherein said prismatic coupler is aTransmissive Right Angle Film.
 47. The optical panel of claim 45,wherein a reflector is disposed immediately adjacent to said prismaticcoupler for reflecting stray light into said plurality of stackedwaveguides.
 48. The optical panel of claim 1, wherein said coupler is adiffractive element.
 49. The optical panel of claim 1, wherein saidcoupler is a holographic element.
 50. A method of producing a thinoptical panel, comprising: laying a first glass sheet in a trough sizedslightly larger than the first glass sheet; filling the trough with athermally curing epoxy; stacking additional glass sheets atop the firstglass sheet, thereby forming a layer of epoxy between each glass sheet;applying uniform pressure to the stack, thereby causing the epoxy toflow to a generally uniform level between glass sheets; baking the stackto cure; cooling the stack; sawing the stack to form an inlet face on aside of the stack and an outlet face on an opposed side of the stack;bonding a coupler to the inlet face of the stack; and fastening thestack, having the coupler bonded thereto, within a rectangular housinghaving an open front which is aligned with the outlet face, therectangular housing having therein a light generator which is opticallyaligned with the coupler.
 51. The method of claim 50, wherein the epoxyis black in color.
 52. The method of claim 50, wherein the epoxy has alower index of refraction than the glass sheets.
 53. The method of claim50, wherein said stacking is repeated until between about 500 and about800 sheets have been stacked.
 54. The method of claim 50, wherein thegenerally uniform level of epoxy is about 0.0002″ in depth between glasssheets.
 55. The method of claim 50, wherein said baking is at about 80degrees Celsius.
 56. The method of claim 50, wherein said sawing isperformed using a diamond saw.
 57. The method of claim 50, furthercomprising polishing the stack with a diamond polisher after saidsawing.
 58. The method of claim 50, further comprising frosting theoutlet face after said sawing.
 59. A method of producing a thin opticalpanel, comprising: individually coating a plurality of glass sheets witha clear cladding material having an index of refraction lower than thatof the glass; vertically stacking a plurality of coated glass sheets;fastening together the plurality of stacked coated glass sheets using anepoxy; applying uniform pressure to the stack; baking the stack to cure;sawing the stack to form an inlet face on a side of the stack and anoutlet face on an opposed side of the stack; bonding a coupler to theinlet face of the stack; and fastening the stack, having the couplerbonded thereto, within a rectangular housing having an open front whichis aligned with the outlet face, the rectangular housing having thereina light generator which is optically aligned with the coupler.
 60. Themethod of claim 59, wherein the epoxy is black in color.
 61. The methodof claim 59, wherein said vertically stacking is performed in a troughsized slightly larger than the surface area of one coated glass sheet.62. The method of claim 61, wherein said fastening comprises filling thetrough with a thermally curing black epoxy before stacking.
 63. Themethod of claim 59, wherein said vertical stacking is repeated untilbetween about 500 and about 800 sheets have been stacked.
 64. The methodof claim 59, further comprising frosting the inlet face and the outletface after said sawing.
 65. The method of claim 59, further comprisingpolishing the inlet face and the outlet face with a diamond polisherafter said sawing.
 66. A method of producing a thin optical panel,comprising: stacking a plurality of glass sheets, each glass sheethaving a width in the range between about 0.5″ and about 1.0″, and alength in the range between about 12″ and 36″; placing a layer of blackultraviolet adhesive between each sheet in the stack; curing each layerof the black ultraviolet adhesive using ultraviolet radiation; sawingthe stack to form an inlet face on a side of the stack and an outletface on an opposed side of the stack; bonding a coupler to the inletface of the stack; and fastening the stack, having the coupler bondedthereto, within a rectangular housing having an open front which isaligned with the outlet face, the rectangular housing having therein alight generator which is optically aligned with the coupler.
 67. Themethod of claim 66, wherein said stacking is repeated until betweenabout 500 and about 800 sheets have been stacked.
 68. The method ofclaim 66, further comprising frosting the inlet face and the outlet faceafter said sawing.
 69. The method of claim 66, further comprisingpolishing the inlet face and the outlet face with a diamond polisherafter said sawing.